1. Field of the Invention
The present invention relates to a vehicle lamp in which the sealing leg of a front lens engages integrally through a sealing material with the sealing groove of a lamp body.
2. Related Art
FIG. 7 shows one example of a conventional vehicle lamp of the type as stated above. The conventional vehicle lamp includes a headlamp in which a front lens 4 is incorporated with the front of a vessel-like lamp body 1 for housing therein a reflector 2 mounted with a bulb 3. A sealing leg 7 formed on the peripheral edge of the front lens 4 is brought into engagement with a sealing groove 5 formed in the front opening of the lamp body 1 via a sealing material 8. The sealing material 8 seals up the inside of the sealing groove 5, whereby a waterproof structure is formed between the front lens 4 and the lamp body 1.
The front lens 4 is also provided with a flange 7a formed on the outer side of the sealing leg 7. The stroke of insertion of the sealing leg 7 into the sealing groove 5 is defined when the flange portion 7a comes into abutment against the front edge of the outer side wall 5a of the sealing groove 5.
Recent demand is that the front opening of the lamp body 1 largely slopes backward or the front lens 4 substantially slopes toward the side of a vehicle so as to harmonize the external configuration of lighting fixtures with the streamline of a vehicle body 9, whereby to decrease air resistance and to seek novelty.
In the aforesaid conventional vehicle lamp, as shown in FIGS. 8 and 9, a base 5b of the sealing groove 5 slopes in harmony with the slope of the front opening of the lamp body 1 so that the depth of the sealing groove 5 is made constant in the widthwise direction of the groove. The base 5b of the sealing groove 5 slopes with respect to a plane F.sub.1 perpendicularly intersecting the direction P.sub.1 in which the sealing leg 7 is inserted when brought into engagement with the sealing groove 5.
Hence, as shown in FIG. 9, the outside wall 5a of the sealing groove 5 is forced to expand if the sealing leg 7 is pressed into the sealing groove 5 relatively strong when inserted therein and the sealing leg 7 is inserted up to a position where the sealing leg 7 is brought into contact with the base 5b of the sealing groove 5. If the sealing leg 7 is thus pressed against the inclined base 5b, the sealing leg 7 is caused to slide (see the two-dotted line of FIG. 9) in the widthwise direction of the groove 5 (direction P'.sub.1 in FIG. 9) along the inclined base 5b due to components of the pressing force applied along the inclined base 5b.
Consequently, there develops nonconformity resulting in causing the sealing material 8 to be forced out of the sealing groove 5 and become soiled, reducing sealing performance because the thickness of the layer of the sealing material 8 becomes irregular in the cross sectional direction of the sealing groove 5, making unobtainable desired proper light distribution in a headlamp in which light distribution is effected by means of the light-distribution control step of the front lens 4 and so forth.